An American Eagle jet is seen through heat ripples as it lands at Sky Harbor International Airport, Monday, June 19, 2017, in Phoenix. American Airlines canceled dozens flights out of and into Phoenix on Tuesday, June 20, 2017, due to extreme heat. The cancellations are for operations by smaller regional jets that have lower maximum operating temperatures than full size jets. The smaller jets can’t operate when it’s 118 degrees or higher. Matt YorkAP

An American Eagle jet is seen through heat ripples as it lands at Sky Harbor International Airport, Monday, June 19, 2017, in Phoenix. American Airlines canceled dozens flights out of and into Phoenix on Tuesday, June 20, 2017, due to extreme heat. The cancellations are for operations by smaller regional jets that have lower maximum operating temperatures than full size jets. The smaller jets can’t operate when it’s 118 degrees or higher. Matt YorkAP

Blistering temperatures force Phoenix to shut down Fresno flights

Blistering heat across the Southwest Tuesday forced the cancellation of two flights connecting Fresno to Phoenix Sky Harbor airport, a major hub in airline travel.

American Airlines flight 5866 , scheduled to depart Fresno Yosemite International Airport for Phoenix at 12:30 p.m., was canceled. Also canceled was American flight 5931 that was to leave Phoenix at 6:30 p.m. for Fresno.

The National Weather Service forecast a Tuesday high for Phoenix of 120 degrees. Extreme high temperatures make the air too thin for aircraft to fly. According to ABC 15, that would prevent a regional aircraft such as the Bombardier CRJ, flown by American, from taking off. The Bombardier is limited to temperatures below 118 degrees. Boeing lists a limit of 126 degrees for its planes and for Airbus, 127 degrees.

The forecast for Phoenix on Wednesday is 116 degrees and for Thursday, 114 degrees. Fresno will be 109 Tuesday, 108 Wednesday and 110 Thursday.